gelgel2 verb (gelled, gelling)1SURE (also jell especially American English) [intransitive] if a thought, plan etc gels, it becomes clearer or more definiteDon’t start writing until the idea has gelled in your mind.2UNITE (also jell especially American English) [intransitive] if two or more people gel, they start working well together as a groupgel withHe did not gel with Chapman.After two days, the group gelled into a team.3DFT (also jell especially American English) [intransitive] if a liquid gels, it becomes firmer or thicker4[transitive] to put gel into your hairgelled hair→ See Verb table